Embodiments of the invention relate to a method for controlling the pressure and/or the flow rate of a fluid, and to a device for controlling the flow rate and/or pressure in a conduit.
It is particularly the case in aircraft, that the task regularly arises, of controlling the flow rate and/or the pressure of a fluid. For example, systems for emergency oxygen supply in aircraft require methods and devices for metering the oxygen.
Basically, there are a multitude of possibilities of controlling the flow rate and/or the pressure of a fluid. These basically fall into two categories: Either the energy necessary for the control is supplied in an electrical manner, as is effected for example in an electrically controllable proportional valve. Alternatively, the control functions in a purely mechanical manner, such as pneumatically or hydraulically, as in a pressure reducer.
These two alternatives thereby have the following disadvantages: Mechanical control units, as is known, operate in a less accurate manner. Moreover, they are typically quite heavy, which is disadvantageous. Control units with electrical components in contrast, although operating in a significantly more accurate manner, disadvantageously always need an energy supply.
Against this background, it is desirable to provide a method for the control of the flow rate or of the pressure of a fluid, which, with regard to apparatus technology, may be implemented in a lightweight constructional manner and which may be applied in a comprehensive and simple manner, as well as with a high accuracy. Moreover, it is desirable to provide a device with which the control of the flow rate and/or the pressure of a fluid is accomplished with the mentioned advantages.